Recent trends have been to look to technology for means to improve health care. However, care must be taken to be sure that new technology is not embraced for its own sake, but to assure that its effects are isolated from other variables and yield positive results. The overall goal of the proposed research is to assess the effect of telemetry on the quality and the cost of advance life support for cardiac arrhythmias. In so doing, we will study specifically the effect of telemetry on the following: 1) the ability of Emergency Medical Technicians-Paramedics (EMT-P) to recognize arrhythmias on a test; 2) the ability of the EMT-P to identify arrhythmias in the field; 3) the accuracy of EKG interpretation by the paramedics and by base physicians using telemetry; 4) the survival of patients with life threatening arrhythmias; 5) the cost of advanced life support; and 6) The reliability of the communications system. The project will be a prospective controlled study utilizing the entire Philadelphia Fire Department mobile intensive care unit system. The research will be conducted utilizing well established collaborative relationships between the University of Pennsylvania, City's Department of Public Health and the Philadelphia Health Management Corporation's Emergency Medical Services Council. The project has major significance in that it should yield definitive information regarding the use of telemetry for diminishing the pre-hospital cardiac deaths. Pre-hospital deaths account for the majority of deaths due to acute cardiac disease, and acute cardiac disease is our leading cause of death.